In the hydrocarbon recovery industry, instrumenting and sensing are more and more regularly desirable. With the advent of optic fiber sensors and the ability to pump them into the downhole environment, operators desires for their use has only increased.
The art of pumping of fibers into the downhole environment is well known and thus its drawbacks and/or limitations have also become well know. For example, because pumping is generally accomplished utilizing a loop of tubular material such as a control line, the distance through which the fiber must travel is twice the distance from the surface to the target location downhole, one leg down and one leg back. This is potentially problematic as the target location becomes more remote (e.g. deeper) from the initiation or surface location. In order to maintain a tractive force on the fiber within the control line, a minimum velocity must be maintained in a carrier fluid. Viscous drag is the basis for the tractive force exerted on the fiber. With increasing distance, the amount of fiber implicated grows and this requires that the velocity of the carrier fluid increase also. With increasing length, however, frictional considerations become more significant until a practical limit is reached above which fiber pumping is simply not considered feasible. This is because there is a practical limit to how much pressure can be employed to drive fluid through the control line without simply bursting the control line at the source. No method has heretofore resolved this issue.